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Old 2010-05-03, 22:34   #1
Mini-Geek
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"Tim Sorbera"
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Default n=390000 discussions and old reservations

Not sure if interest in this will continue, but I'll help a bit.
Reserving k=500k-1M. This is a rather small and easy chunk of work. One core of my i5, taking 0.640 ms per iteration, (or 4 minutes and 9.6 seconds per candidate) should finish all 262 candidates in about 18 hours and 10 minutes. A multiple-million reservation would be a more typically-sized piece of work for most people.

Last fiddled with by Oddball on 2010-05-24 at 00:07 Reason: changing title
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Old 2010-05-04, 18:41   #2
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This file is too undersieved to do primality testing already. With NewPGen (I'm running an i5 on 32-bit XP; tpsieve with one thread is around half the speed) I can eliminate about one k every 2 seconds compared to one LLR test every 250 seconds. Unless I'm mistaken, (or shouldn't be ignoring things like accounting for double checks) that means that the sieve depth needs roughly 7 doublings (2 with 7 doublings is 2*2^7=256, just about 250) before it's optimally sieved for 32-bit (if you can get 64-bit sievers, sieve speed might approximately double, which might mean about another doubling). That puts it at roughly 400-450T (3.33*2^7=426.24) before primality tests ought to be run on this range.

I'm not putting a serious effort to sieving this at the moment, but I sieved it to 3.38T (107 factors in 267 seconds) with NewPGen. The new file is attached. (you might need to rename it to remove the ".zip" before it'll open, as the forum doesn't like .7z but only .7z will compress to under the attachment limit)
Attached Files
File Type: zip 390-3.38T.7z.zip (191.7 KB, 192 views)

Last fiddled with by Mini-Geek on 2010-05-04 at 19:04
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Old 2010-05-05, 04:57   #3
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Hmmm, it looks like I can't edit the first post. Maybe that's because I'm not a mod. But anyway, I'm reserving 1M-1.2M. So far, we have:

Code:
Range		Reserved by		Status		Primes found
0.0M-0.3M	Oddball			complete	0
0.3M-0.5M	Oddball			complete	0
0.5M-1.0M	Mini-Geek		complete	0
1.0M-1.2M	Oddball			in progress	?
I'm planning to sieve more, so that range might not get done for some time.

Last fiddled with by Oddball on 2010-05-05 at 05:11 Reason: typo
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Old 2010-05-06, 17:45   #4
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My Core i5 can help sieving with all 4 cores (running 64-bit Linux of course). I just want to ensure that neither my nor anyone else's CPU hours would be wasted.
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Old 2010-05-06, 20:51   #5
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Quote:
Originally Posted by gribozavr View Post
My Core i5 can help sieving with all 4 cores (running 64-bit Linux of course). I just want to ensure that neither my nor anyone else's CPU hours would be wasted.
Thanks for offering to help out!

Right now, just sieve 10G-150G to 8.1T. When you're done, merge that file into the 1M-10G file (which is also sieved to 8.1T) uploaded here:

http://www.sendspace.com/file/dfee42

You can then sieve the whole 1M-150G file at once from that point on. I couldn't do that because my PC didn't have enough RAM, but the RAM that usually comes with a core i5 should be enough to do the job.

I'll keep the old system for the credits the same. If/when a twin is found, the finder shares the credit with both the top siever and the top LLR tester.
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Old 2010-05-06, 20:55   #6
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Those of you who want to jump right into LLR testing can start by downloading the attached file. It contains k=1M-10M, sieved to 8.1T. There are about 470 candidates per 1M.
Attached Files
File Type: txt twin.txt (67.0 KB, 196 views)
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Old 2010-05-07, 10:29   #7
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Quote:
Originally Posted by Oddball View Post
Right now, just sieve 10G-150G to 8.1T.
Could you point me to the file? I don't seem to see it.
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Old 2010-05-07, 11:46   #8
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Quote:
Originally Posted by gribozavr View Post
Could you point me to the file? I don't seem to see it.
I don't think it exists yet, you'll have to start it from the beginning.
Apparently Oddball decided to change the scope of this. The only older files posted were for k=200k-200M, and now he's talking about 1M-10G and 10G-150G.
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Old 2010-05-07, 15:16   #9
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I haven't been on mersenneforum for quite some time, but I'll give this project a try. Reserving 1.2M-1.4M.

Quote:
Originally Posted by Mini-Geek View Post
Apparently Oddball decided to change the scope of this. The only older files posted were for k=200k-200M, and now he's talking about 1M-10G and 10G-150G.
Another possibility could be that 1-10G was sieved, but he only chose to release 200k-200M because the whole 1-10G sieve file would take too long to download. As far as I can tell, he mentioned 1-150G all along, but he only sieved 1-10G because he lacked the resources to do so.

From: http://www.mersenneforum.org/showthread.php?t=13375

Quote:
I'm proposing a new goal: test n=390,000 from k=1-150G.
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Old 2010-05-08, 09:01   #10
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Quote:
Originally Posted by Historian View Post
I haven't been on mersenneforum for quite some time, but I'll give this project a try. Reserving 1.2M-1.4M.
Welcome to TPS!

Quote:
Another possibility could be that 1-10G was sieved, but he only chose to release 200k-200M because the whole 1-10G sieve file would take too long to download. As far as I can tell, he mentioned 1-150G all along, but he only sieved 1-10G because he lacked the resources to do so.
That is correct.

Anyway, I'm done with my old range (results attached). No primes were found, so I'm getting 1.4M-1.7M. Here's the current status:
Code:
Range		Reserved by		Status		Primes found
0.0M-0.3M	Oddball			complete	0
0.3M-0.5M	Oddball			complete	0
0.5M-1.0M	Mini-Geek		complete	0
1.0M-1.2M	Oddball			complete	0
1.2M-1.4M	Historian		complete	0
1.4M-1.7M	Oddball			in progress	?
1.7M+		available
Attached Files
File Type: txt lresults.txt (9.3 KB, 190 views)
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Old 2010-05-08, 09:13   #11
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Looking at the First Twin k (see bottom, first graph) the estimated k-value for n=333333 using the formula k=0.2784*n^1.9652 is k=19871455920.
The real values was k=65516468355.

So for n=390000 it's estimated for k=27053869866 or about 27G.
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